NG TS 3.03.09 PDF

PURPOSE AND SCOPE

The Technical Specifications for all new plant, equipment, apparatus and services, for use on the National Grid UK Electricity Transmission system are contained in a three level hierarchy of documents. Level 1 covers ratings and general requirements, Level 2 covers major plant categories and Level 3 covers specific related plant functions.

This document is a Level 3 specification, which describes the functional and performance requirements for Winding temperature indicators (WTI) to be used in all liquid immersed Power Transformers, Reactors and Quad boosters at National Grid switching stations.

The document is intended to cover both WTI systems provided as part of an overall transformer installation contract and individual supply of WTI equipment for retro-fit or repair purposes. When considering individual WTI equipment supply, requirements that are clearly written to address overall transformer installation issues should be disregarded – where there is any doubt as to the applicability of any part of this document, clarification must be sought from National Grid.

This document permits the offering of both electro-mechanical and electronic WTI solutions, where electro-mechanical solutions have electronic elements incorporated to achieve the overall functionality required, any such electronic elements shall also comply with the relevant parts of this specification as written for electronic WTIs.